Urinary incontinence is the loss of voluntary control to retain urine. Urinary incontinence may be the result of a number of causes, such as old age, disease, pregnancy or trauma, or no apparent cause, as is the case with urge incontinence. Some patients may experience urinary incontinence during stressful events, such as sneezing, laughing, coughing, lifting, or other activity that puts pressure on the bladder.
Some patients suffering from urinary incontinence may deal with the condition by conservative measures, such as performing exercises to strengthen the outer urethral sphincter. For some patients, however, such conservative measures are ineffective. In a healthy human being, the internal and external urethral sphincters contract to prevent the escape of urine, the external sphincter being under the voluntary control of the patient. In some patients, however, the patient may have some control over the external sphincter, but one or both sphincters lack the ability to maintain closure of the urethra and prevent the escape of urine.